Constraints on the geodynamic evolution of the southern Superior Province: U-Pb LA-ICP-MS analysis of detrital zircon in successor basins of the Archean Abitibi and Pontiac subprovinces of Ontario and Quebec, Canada

• Published in: Precambrian research 2017-05, Vol.292, p.398-416
• Main Authors: Frieman, Ben M., Kuiper, Yvette D., Kelly, Nigel M., Monecke, Thomas, Kylander-Clark, Andrew
• Format: Article
• Language: English
• Subjects: Abitibi greenstone belt; Neoarchean tectonism; Provenance analysis; Syn-deformational basins; U-Pb geochronology
• ISSN: 0301-9268; 1872-7433
• DOI: 10.1016/j.precamres.2017.01.027

•We present >2100 detrital zircon U-Pb LA-ICP-MS analyses from successor basins of the Abitibi and Pontiac subprovinces.•Samples contain 2–21% Mesoarchean zircon, which must have been derived from a juxtaposed orogenic hinterland.•Comparison to >1500 published U-Pb zircon ages indicate that sources include composed of several amalgamated Meso- to Neoarchean subprovices.•Older basins contain low proportions of Mesoarchean zircon, while younger basins contain higher proportions, likely due to progressive hinterland uplift.•Patterns of sedimentation, deformation, and felsic plutonism are consistent with modern-style accretionary tectonic processes. To investigate the tectonic development of the southern Superior Province, new U-Pb laser ablation inductively-coupled mass-spectrometry analysis of detrital zircon was conducted on graywacke samples from successor basins of the Abitibi and Pontiac subprovinces. The three successor basin successions investigated are the 2690–2685Ma Porcupine assemblage and the 2679–2669Ma Timiskaming assemblage of the Abitibi subprovince, and the ∼2682Ma sedimentary rocks of the Pontiac subprovince. Predominately Neoarchean zircon grains (80–95% of the total zircon population) reflect local sources in the Abitibi and Pontiac subprovinces. The successor basins were deposited within 100Ma of the majority of the detrital zircon grains primary crystallization ages, which is consistent with patterns observed at modern convergent margin settings. Porcupine assemblage samples contain ∼5% Mesoarchean zircon, while Pontiac subprovince and Timiskaming assemblage samples contain ∼18% and ∼13%, respectively. No local Mesoarchean sources exist in the Abitibi or Pontiac subprovinces, suggesting input from an adjacent hinterland. The higher proportion of Mesoarchean zircon in the Timiskaming assemblage relative to the Porcupine assemblage suggests that detritus from the hinterland was more prevalent during the later stages of collision, probably as a result of progressive uplift and denudation of the hinterland. The high proportion of Mesoarchean zircon in the Pontiac subprovince sedimentary rocks may reflect an additional Mesoarchean source. Comparison to previously published geochronology data for the Superior Province indicates that the hinterland was to the northwest and is, in part, composed of the Winnipeg River, Marmion, and Opatica subprovinces. Patterns of contractional deformation, successor basin formation, and felsic plutonism progres